Not going to say all are rated for #8, but some common definite purpose contactors I used to use frequently I am pretty certain were rated to accept 8 AWG conductors. They would have been Cutler Hammer contactors.Your where I was at till I looked into this further and was surprised to learn about this #10 limitation. Number 8 fits too, but that makes this a connection that is not UL listed. This exposes a contractor to unintended additional liability. Then one has to wonder and question why the component manufacturer published this wire size as the limitation? They must have their reasons. Then I add a UL listed connector approved for the size wire I am connecting but technically this limitation is still in play.
i could see this being addressed by UL. But if they don't, there has to be an approved way of connecting larger wire sizes to Binding Head Screw terminals.
I do know Square D NEMA size 1 contactors also accept 8 AWG under a similar style terminal.